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Bharadwaj S, Urner TM, Cowdrick KR, Brothers RO, Boodooram T, Zhao H, Goyal V, Sathialingam E, Wu YC, Quadri A, Turrentine K, Akbar MM, Triplett SE, Bai S, Buckley EM. Stand-alone segmentation of blood flow pulsatility measured with diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2024; 15:6052-6062. [PMID: 39421785 PMCID: PMC11482157 DOI: 10.1364/boe.533916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 09/04/2024] [Accepted: 09/07/2024] [Indexed: 10/19/2024]
Abstract
We present a stand-alone blood flow index (BFI) pulse segmentation method for diffuse correlation spectroscopy that uses a wavelet-based representation of the BFI signal at the cardiac frequency in place of an exogenous physiological reference. We use this wavelet-based segmentation method to quantify BFI waveform morphology in a cohort of 30 healthy adults. We demonstrate that the waveform morphology features obtained with the wavelet approach strongly agree with those obtained using an exogenous blood pressure reference signal. These results suggest the promise of stand-alone wavelet-based BFI segmentation for quantifying BFI waveform morphological features.
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Affiliation(s)
- Srinidhi Bharadwaj
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Tara M. Urner
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Kyle R. Cowdrick
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Rowan O. Brothers
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Tisha Boodooram
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Hongting Zhao
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Vidisha Goyal
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Eashani Sathialingam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Yueh-Chi Wu
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Ayesha Quadri
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Katherine Turrentine
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Mariam M. Akbar
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Sydney E. Triplett
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
| | - Shasha Bai
- Department of Pediatrics, Emory School of Medicine, Atlanta, Georgia 30322, USA
| | - Erin M. Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30322, USA
- Department of Pediatrics, Emory School of Medicine, Atlanta, Georgia 30322, USA
- Children's Research Scholar, Children's Healthcare of Atlanta, 2015 Uppergate Dr., Atlanta, Georgia 30322, USA
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Roy S, Wu J, Cao J, Disu J, Bharadwaj S, Meinert-Spyker E, Grover P, Kainerstorfer JM, Wood S. Exploring the impact and influence of melanin on frequency-domain near-infrared spectroscopy measurements. JOURNAL OF BIOMEDICAL OPTICS 2024; 29:S33310. [PMID: 39323492 PMCID: PMC11423252 DOI: 10.1117/1.jbo.29.s3.s33310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 08/12/2024] [Accepted: 08/30/2024] [Indexed: 09/27/2024]
Abstract
Significance Near-infrared spectroscopy (NIRS) is a non-invasive optical method that measures changes in hemoglobin concentration and oxygenation. The measured light intensity is susceptible to reduced signal quality due to the presence of melanin. Aim We quantify the influence of melanin concentration on NIRS measurements taken with a frequency-domain near-infrared spectroscopy system using 690 and 830 nm. Approach Using a forehead NIRS probe, we measured 35 healthy participants and investigated the correlation between melanin concentration indices, which were determined using a colorimeter, and several key metrics from the NIRS signal. These metrics include signal-to-noise ratio (SNR), two measurements of oxygen saturation (arterial oxygen saturation,SpO 2 , and tissue oxygen saturation,StO 2 ), and optical properties represented by the absorption coefficient (μ a ) and the reduced scattering coefficient (μ s ' ). Results We found a significant negative correlation between the melanin index and the SNR estimated in oxy-hemoglobin signals (r s = - 0.489 , p = 0.006 ) andSpO 2 levels (r s = - 0.413 , p = 0.023 ). However, no significant changes were observed in the optical properties andStO 2 (r s = - 0.146 , p = 0.44 ). Conclusions We found that estimated SNR andSpO 2 values show a significant decline and dependence on the melanin index, whereasStO 2 and optical properties do not show any correlation with the melanin index.
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Affiliation(s)
- Shidhartho Roy
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Department of Electrical and Computer Engineering, Pittsburgh, Pennsylvania, United States
| | - Jingyi Wu
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Jiaming Cao
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Joel Disu
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Sharadhi Bharadwaj
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Elizabeth Meinert-Spyker
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Pulkit Grover
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Department of Electrical and Computer Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Neuroscience Institute, Pittsburgh, Pennsylvania, United States
| | - Jana M. Kainerstorfer
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Department of Electrical and Computer Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Neuroscience Institute, Pittsburgh, Pennsylvania, United States
| | - Sossena Wood
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Department of Electrical and Computer Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Neuroscience Institute, Pittsburgh, Pennsylvania, United States
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Kedia N, McDowell MM, Yang J, Wu J, Friedlander RM, Kainerstorfer JM. Pulsatile microvascular cerebral blood flow waveforms change with intracranial compliance and age. NEUROPHOTONICS 2024; 11:015003. [PMID: 38250664 PMCID: PMC10799239 DOI: 10.1117/1.nph.11.1.015003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/15/2023] [Accepted: 12/26/2023] [Indexed: 01/23/2024]
Abstract
Significance Diffuse correlation spectroscopy (DCS) is an optical method to measure relative changes in cerebral blood flow (rCBF) in the microvasculature. Each heartbeat generates a pulsatile signal with distinct morphological features that we hypothesized to be related to intracranial compliance (ICC). Aim We aim to study how three features of the pulsatile rCBF waveforms: the augmentation index (AIx), the pulsatility index, and the area under the curve, change with respect to ICC. We describe ICC as a combination of vascular compliance and extravascular compliance. Approach Since patients with Chiari malformations (CM) (n = 30 ) have been shown to have altered extravascular compliance, we compare the morphology of rCBF waveforms in CM patients with age-matched healthy control (n = 30 ). Results AIx measured in the supine position was significantly less in patients with CM compared to healthy controls (p < 0.05 ). Since physiologic aging also leads to changes in vessel stiffness and intravascular compliance, we evaluate how the rCBF waveform changes with respect to age and find that the AIx feature was strongly correlated with age (R healthy subjects = - 0.63 , R preoperative CM patient = - 0.70 , and R postoperative CM patients = - 0.62 , p < 0.01 ). Conclusions These results suggest that the AIx measured in the cerebral microvasculature using DCS may be correlated to changes in ICC.
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Affiliation(s)
- Nikita Kedia
- University of Pittsburgh School of Medicine, Department of Neurological Surgery, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Michael M. McDowell
- University of Pittsburgh School of Medicine, Department of Neurological Surgery, Pittsburgh, Pennsylvania, United States
| | - Jason Yang
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Jingyi Wu
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Robert M. Friedlander
- University of Pittsburgh School of Medicine, Department of Neurological Surgery, Pittsburgh, Pennsylvania, United States
| | - Jana M. Kainerstorfer
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
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